Field Trip
by Elf Cakes
Summary: Professor Snape chaperones the Gryffindor and Slytherin fifth years on a field trip through a eukaryotic cell. A paper written for my biology class.


**A couple of notes from the author:** This is actually a paper I wrote for my General College Biology I class. The assignment was essentially to assume the role of a tour guide and lead a group of people on a tour through a eukaryotic cell. My professor emphasized that we should be creative and have some fun with the project. He also told us that he used to assign something similar to ninth graders, and that his college students have never come close to doing as well creatively as the ninth graders did. So, as not to be outdone by ninth graders, I tapped into my "inner child", and this is what I came up with.

Please keep in mind that while this is loosely based on Harry Potter canon, the assignment was to write about the structure and function of a cell, not to write a really good fan fiction. I feel that because of this, in places, the story progresses all together too quickly, and that the characterizations are perhaps a little bit exaggerated. I did have to keep it "short", and the focus really couldn't be on canon characters. This is a blatant self-insert, as that was also part of the assignment.

With that, I present to you a really lame Harry Potter fan fiction, but fairly good biology paper.

It was a sunny morning in March at the Hogwarts School of Witchcraft and Wizardry. The Gryffindor and Slytherin fifth years sat in the Potions classroom, eagerly awaiting the arrival of Professor Snape. Perhaps "eagerly" is not the best way to describe the students' attitude towards the day's lesson. "Anxiously and slightly worriedly" is slightly more synonymous. That morning, the fifth years were to take a field trip to see the inside of a typical animal cell.

A rather reluctant Professor Snape grumbled as he made way to the Potions classroom. He had been convinced, or rather, forced by Albus Dumbledore to chaperone the students on their field trip. _They never pin this rubbish on the Defense Against the Dark Arts professors_, he thought grumpily to himself. Severus Snape pushed the doors open with the same kind of dramatically dark finesse he tended to favor, and his students immediately quit talking amongst themselves and dropped into their seats.

"As you all are well aware, the new Educational Decrees set forth by the Ministry of Magic require that students must have basic knowledge of biology to pass their Ordinary Wizarding Levels," the professor paced as he spoke. "In compliance with these new regulations, today we will take a tour of the inside of an animal cell."

A particularly bright student known as Hermione Granger raised her hand. Snape ignored her. Hermione sat next to Harry Potter, who muttered something about Snape being the oddest choice of all the staff for an educational tour. "Five points from Gryffindor for that remark, Potter."

Hermione still had her hand raised.

Just then, a young woman with dark hair walked somewhat awkwardly through the large doors. She carried a small glass container in her left hand. "You are the tour guide, I presume?" Snape asked.

"Yes."

"And your name?"

"Liz."

Professor Snape observed his class, and the class watched the tour guide take her wand out of a small black handbag. Suddenly, Snape looked a bit uncomfortable. He wasn't quite sure if he trusted this tour guide, who was probably just barely past her Nastily Exhausting Wizarding Tests (also known as the N.E.W.T.s), to shrink anybody down to such a ridiculously small size. "Are you sure you're qualified to do this?" He asked.

"Relax. I've only ever messed this up once."

Snape stared in horror at the young tour guide. The tour guide ignored him and walked to the front of the class. "Hello! My name is Liz, and I'll be your tour guide today. I'm quickly going to run through the basic procedure with you guys and answer any questions you might have, then we'll get started, okay?"

"Okay," chorused the class.

Liz held up the glass container for the class to see. "In this vial is a human cell. You can't see it now because it is too small. Of course, it seems pretty silly to do a tour of something so small you can't even see it. How would we all get in? Well, I will perform a shrinking spell that will allow us to fit inside the cell with plenty of room to spare. We will start in the cell's nucleus, and then work our way out. After that, we'll return to our normal size. Questions?"

Hermione's hand shot up a second time. "I have a question."

"Yes… uh… name?"

"Hermione Granger. Will we be able to see the cell's cytoskeleton? None of the books I've read have described it all that well, and I'm eager to see one for myself."

"Good question! Yes, we'll be able to see plenty of the cytoskeleton. If we're lucky, we might even be able to see it break apart or reform! Any other questions?"

No other hands were raised. "Well, if that was it, I think we should get started. Everyone, gather 'round!"

The class and Professor Snape crowded around the guide, who was holding her wand in her right hand, and touching the vial on a small table with her left. "_Reducio_!"

Before the class even realized what was happening, they were already small enough to fit inside of the cell's nucleus. The students, professor, and tour guide were all standing on a floating platform of sorts. "This platform is what will help us travel through the cell without interfering with its natural processes. I ask that no one try to get off of the platform. I'm sure your professor will have no problem taking house points from any one of you should you try to do anything obnoxious. Right, Professor Snape?"

"Quite right," he agreed. Professor Snape was beginning to look a bit relieved knowing that he had made it in one piece.

"If you have any questions along the way, do feel free to ask. If you would like to see anything closer or in more detail, just let me know. Shall we begin the tour?"

A collective "yes" was heard.

"Alright! Well, here we are in the cell's nucleus. The nucleus is the most prominent feature of most eukaryotic cells. This is where the DNA –that is, deoxyribonucleic acid- is located. Although it is a fairly large organelle, in this particular cell, it is only about 5 mm. At this moment, we are all significantly smaller than that. We are in the nucleus' center, which is called the nucleolus. This is where the ribosomal RNA is synthesized."

The railed platform moved around the ribosomal RNA structures as Liz spoke. Many of the students, primarily the Gryffindor students, moved close to the railings to get a better look. A blond Slytherin boy, Draco Malfoy, and his two friends Crabbe and Goyle, stood far away, sulking. Harry Potter and his redheaded friend Ron Weasley stood talking quietly while Hermione jotted down notes.

Liz continued. "Ribosomal RNA is put together with proteins. This process creates what is called a ribosomal subunit. These subunits will eventually pass through the nuclear pores and connect with each other to form ribosomes.

The platform stopped circling and began to head straight.

"Now if I could have your attention," Liz said, "We are now leaving the nucleolus. Soon, you will be able to see the chromatin. Anyone want to offer a definition of chromatin?"

Hermione looked up from her notes. "Chromatin is the DNA organized into fibrous structures. Before a cell divides, it will start to coil and form chromosomes."

Snape looked rather irritated. He probably would have deducted more points from Gryffindor, but he thought it was neither the time nor the place. Instead, he decided to let the guide do her job and get the bloody tour over with. Much to his dismay, however, Liz was not unhappy with Hermione's _outburst_.

Liz looked rather impressed. "Very good! That's exactly right. As we move closer, we will be able see the proteins that make up the chromatin. In just a few minutes, the chromatin should begin to form chromosomes. The chromosomes are essentially chunks of genetic material that rule cell function and are the codes for inheritance. This cell will make forty-six chromosomes."

The group waited until the chromosomes started to form. Once everyone had a good look at the chromosomes, the platform sped up and headed towards the nearest part of the nuclear envelope. As it did so, Liz explained that the nuclear envelope was made up of two different lipid bilayers and that the bilayers were separated by an average of 20-40 nm. As the group approached the envelope, a boy from Gryffindor raised his hand shyly.

"Go ahead," Liz urged.

"What are the nets on the inside of the envelope?"

"Those are called nuclear lamina… umm, your name?"

"Neville Longbottom."

"Neville. Nuclear lamina holds the shape of the nucleus, and they are made up of protein filaments." Liz paused for a moment, and then addressed the group, "If you will all notice the protruding structure just in front of us. That is called a pore. Pores are openings within the nuclear envelope and are places where the two lipid bilayers that make up the envelope are fused together. The pores strictly regulate what leaves the nucleus and what goes in, so be prepared to be prodded at in a tightly enclosed space."

The experience of being in the pore was one not to be forgotten. It stunk, and there was hardly enough room to breathe. The platform moved slowly through the pore, and still managed to get stuck a couple times. Most of the students thought the experience of being in the pore was thrilling and a great change of pace from Professor Snape's characteristically dull lectures. Draco Malfoy was the exception. He believed he shouldn't have ever had to go inside such a repulsive thing (never mind the fact that he was, and still is, made up entirely of such structures!) and promptly began to yell threats to the poor tour guide. "My father will have you fired or worse for this! You won't get away with having put me in danger!"

Once the platform left the pore, Draco calmed down. He still shot Liz scowls and eye-rolls every once and a while during the rest of the tour. Liz was used to it. The pore always gets the better of some of the guests.

Outside of the pore, but now in some other strange thing, the students looked around astounded. "Well, here we are in the endoplasmic reticulum. More specifically, we are in the rough endoplasmic reticulum. Not really the sort of place you'd take someone on a first date, but it is interesting enough. The mole-like things you see sticking out are ribosomes. The endoplasmic reticulum is continuous with the nuclear envelope.

"While we are waiting for the platform to make its way to our next destination, I can tell you a bit more about ribosomes. As you all know, ribosomes are made up of ribosomal RNA and protein. What you might not know is that the ribosomes produce a cell's proteins.

"Moving on, now we are in the smooth endoplasmic reticulum. Unlike the rough endoplasmic reticulum, the smooth endoplasmic reticulum does not have any ribosomes. Smooth endoplasmic reticulum is important because it produces various lipids, including hormones. In certain cells, the smooth endoplasmic reticulum store carbohydrates and break them apart for energy. In other cells, this organelle can help detoxify things that are poisonous to our bodies."

A bunch of bored Slytherins looked up, but none of them seemed to have any questions. A Slytherin girl with short hair leaned over to Draco Malfoy and said quietly that she wondered when the tour would end. Draco smirked. The platform reached another interesting, twisted looking organelle.

"This is the Golgi apparatus. You can think of it as a cell's owlry, because it receives and ships things off to other parts of the cell. One part of this organelle, the _cis _face, receives things. This is where we are now. We will leave through the opposite side, the _trans_ face, which ships things. On the journey from the _cis _face to the _trans_ face, phospholipids and proteins are often modified. The Golgi is also like a factory muggles use to make things in that certain parts of the Golgi do specific parts of the work, then pass the product along to another part of the Golgi, which does another part of the work. It's a lot like an assembly line."

The platform made its way out of the Golgi apparatus, and into the cytosol. Certain students noted how "icky" or "gross" the cytosol was. "Hermione, this part of the tour may be of interest to you, since you wanted to see the cytoskeleton," Liz said. The Hogwarts fifth years watched as the thin, fibrous lines connected all of the organelles.

"The cytoskeleton serves to give structure to the cell and its organelles, and is surprisingly strong. Interestingly enough, it can break apart and reassemble in another part of the cell. It is both strong and flexible."

Eventually, the platform reached a globular-like organelle. "This is a lysosome," Liz announced. "Basically, it digests a cells 'food'. The membrane you see surrounds hydrolytic enzymes. We won't actually go inside of the lysosome, because you could accidentally be digested with the other macromolecules."

"Can we throw Filch in there?" Some student joked.

"Pardon?" Liz asked.

"Ten points from Gryffindor," Snape interrupted.

The platform quit circling the lysosome and headed towards another strange thing. It looked like a bloated yam on a bad day. This thing was bigger than the lysosome but smaller than the other organelles. "We're on our way to a mitochondrion," Liz informed the students. "The mitochondria generate ATP. In plain English, they make energy from sugars and fats."

Liz produced a cardboard carton full of plastic goggles. She took a pair out for herself, then passed the carton to the nearest student. "Pass these around. You'll be glad you wore them."

As the carton was being passed around, Liz explained that they were about to see "some pretty sweet chemical reactions" and that the goggles would protect their eyes.

The goggles went on and the platform entered the mitochondrion. Amazed students watched as the ATP was created. Even the usually "bored" Slytherin group was at least mildly interested. Even Draco seemed to forget the cytosol in his hair and even stopped glaring at Liz for a few minutes. The mitochondrion was a happy place.

A few moments later, the platform exited the mitochondrion and the students were talking excitedly about what they had seen. Liz planned to wait a moment to let the kids calm down on their own, but it turned out she didn't need to. Snape was already threatening to deduct more points for unruly behavior, and that seemed to do the trick.

The platform began to circle around a small organelle. When the fifth years were quiet, Liz spoke. "This is the vacuole. There are several different kinds of vacuoles that different cells use. Freshwater protists have specific vacuoles that serve to pump water out of the cell. Many plant cells have a very large vacuole called central vacuole. These central vacuoles store energy and break down wastes. However, we are not touring the cell of a water protist or a plant, but of a human. The vacuoles in human cells are called food vacuoles. These food vacuoles take in food at the plasma membrane, then fuse with a lysosome."

After a bit of awkward silence, the tour guide announced that they were almost through with the tour, and that their final stop would be the plasma membrane. As they approached the membrane, Liz started to speak again. "The plasma membrane is kind of like a wall around a castle. It can let things out and let things in, but it also protects the things inside. Unlike a wall, the membrane is very flexible. It has enough surface area to get rid of wastes and receive what it needs quickly enough to support the structures inside. The plasma membrane is a bilayer of phospholipids and has an assortment of proteins embedded into it. By the way, hang on to your seats! This might be even rougher than the pore."

The platform and its contents squeezed through the plasma membrane and landed on a thick clear surface. They were on the bottom of the glass vial. "Okay! Everybody ready to go back to their regular size?"

There were a few nods and some muttered yeses. Liz took that as a go ahead and yelled "_Engorgio_!"

Within seconds, everybody was back to their normal size, piled on top of one another in a heap near the small table. The table had tipped over under the sudden weight of so many people, and the glass vial had shattered as everyone expanded. A very exhausted Professor Snape waved his students off with a quick "class dismissed" as the fifth years sorted themselves out and dusted themselves off.


End file.
